Lansing — One day after being sued over a controversial ballot box citizenship question, Secretary of State Ruth Johnson said Tuesday there are an estimated 4,000 noncitizens on Michigan’s voter rolls.

The estimate is based on the state’s access to citizenship information for one-fifth of the population, Johnson said, adding the federal government won’t give her access to more citizenship data.

Johnson said the results of a “very tedious” analysis of 58,000 driver’s licenses and state-issued identification cards found 963 noncitizens registered to vote.